135 macro

[xosni]

I was wondering if this lens is optically optimised for 1:1

reproduction ratio. yes i know its max. magnification without tubes

is 1:3 and with tubes 1:1, but is it optically optimised for these

degrees? in other words, is it a real macro lens or jus on of those

lenses that focuses a little closer and labeled macro? Would I be

better off with a reverse ring? ( I already had great results with

such technique)

 

thanks

Xosni

[douglas_green1]

Most true macro lenses are optimized for between 1:2 and 1:10. I'd say that is true with the Pentax 6x7 135mm lens as well. I think that this lens is better at 1:1 without the reversing ring, but the standard 105mm lens is better with the reversing ring.

[cy soto]

Actually with the Extension Tube set and the 135mm Macro you end up getting a 1/0.98 (but that's only important if you absolutelly need it to be at 1/1). <p>I own and use this combination extensivelly and I can assure you that the lens is optimized for Macro work up to 1/1. After that you start getting vignette (or light loss on the edges of your image). If you want to get more than a 1/1 you'll need to invest in the bellows system that Pentax offers and then you'll also probably going to need another lens (maybe something wider). <p>A reversing ring works great too but I personally prefer to keep my Extension Tubes and 135 Macro because they are easy to use and I have never had the need to do any Macro work with a magnification greater than a 1-to-1. Another great thing with this set-up is that you can use your TTL meter instead of having to calculate light-loss manually.